Effects of Thiobacillus, sulfur and organic fertilizer on phosphorus absorption in Maize

To investigate simultaneous effects of Thiobacillus bacteria, sulfur, and organic fertilizer treatments on chemical forms and quantity of phosphorus absorption by corn, an experiment was conducted based on completely randomized design using eight treatments and three replications in a greenhouse located in Hashtgerd, in 2014. Treatments included control, Thiobacillus, sulfur, organic fertilizer, and two ways and three ways combinations of these factors. Results showed  that the highest and lowest yield, root dry weight, root fresh weight, shoot weight, and phosphorus uptake were obtained in the Thiobacillus + sulfur +organic fertilizer treatment and control treatment (without any added Thiobacillus, sufur, and organic fertilizer), respectively. Thiobacillus + sulfur +organic fertilizer treatment caused significant change in inorganic and organic phosphorus elements and enhanced available phosphorus in soil, so that the highest available phosphorus was related to the treatment number eight with 16.22 mg/kg soil and this treatment showed four more mg of available phosphorus compared with control treatment. On the other hand, the Thiobacillus +sulfur treatment resulted in more reduction in mineral forms of phosphorus including dicalcium phosphate and apatite joint phosphorus compared with other treatments. The most organic and total phosphorus in soil was observed in sulfur + organic phosphorus and Thiobacillus + organic phosphorus treatment, respectively. Taken together, results of this study showed that using Thiobacillus bacteria along with sulfur and organic fertilizer would result in enhanced phosphorus uptake and improved phosphorus status in the plant, which would cause more reduction in chemical fertilizers in extensive scale.